Google image search is a great way to locate images, but sometimes you don't know exactly what you're looking for. Google's just started rolling out a new feature that'll let you search more vaguely for a particular image and then narrow down the results by sorting the images based on their category. To try it out, you just perform an image search and click "Sort by subject" in the lefthand menu.

Note: this feature is still rolling out so you may not see it right away, but check out the video above for a demo.